Impossible to return faulty equipment to the store as instructed, employees who originally handed it to me said 'no'.

For two months, I have been trying to cancel my account and return faulty equipment, to no avail. I have followed instructions exactly, and met with nothing but obstacles, 'do it yourself' instructions, and conflicting internal policies.
The first (black) gateway had a defective fan and overheated within an hour, so I returned it to the nearest brick and mortar store as directed by email, who exchanged the black gateway then and there for the newer white gateway ( I don't know the model numbers). That unit never got more than three bars, and stalled for 36 hours at 44% complete in an upgrade process. In less that 24 hours the phone that came with the bundle likewise demanded software "patch", a euphemism for 'repair'. I returned a second time to the brick and mortar store to cancel and return all the equipment, but they refused to accept it due to their own internal policies. Due to my health I (we all) need the most reliable communications possible, but with their equipment, I was disconnected.
Calls to customer service have without exception been answered by personnel with language barriers, seemingly not to know the difference between "can't" and "won't", nor do they understand that without a gateway or modem, I cannot receive email; or that since I don't have a printer, I can't print a UPS label. I was cast adrift. The idea that someone would use a telephone for voice calls and nothing else was literally beyond their comprehension, I had to repeat that fact three times to the same representative. LIkewise I had to repeat myself that I do not download "apps" to try to make their equipment function as represented. 
Now I am being charged $54 for the first defective modem "the equipment your returned was damaged" and no way to reply "it was defective upon delivery", as well as a $135 fee for a phone I didn't use, because they couldn't coordinate with ATT, to re-assign my number, and whose brick and mortar was within sight. Since they refused to accept the newer gateway, the fee has been turned over to a collection agency, for nearly $1000.
After repeated calls to customer service, they told me I could forward the UPS label file attachment to a different T-Mobile location, where they could print it, but I still had to hand deliver to a UPS drop off, because "they're not allowed to" schedule a pickup, I guess. Upon dialing that location, no one answered the phone and my call was disconnected. On the second attempt, the manager answered, to offer only more roadblocks; I can’t forward the UPS label file to them because they have firewalled the office from incoming emails for security reasons, (breaches) at their own physical location, in other words, the bank is so 'secure' customers can no longer make a deposit or withdrawal. All she could offer was she had ten years experience, forward the UPS label file to a printing service at my own expense and inconvenience, physically go there, deliver it myself to UPS and hope someone can sort things out.
Headspinning for a telecom company. If it flies a T-Mobile banner, people expect and deserve the same service, whether brick and mortar, on-line sales, or a shopping mall kiosk. I followed their initial instructions to return to the nearest store, now it all appears to be a fine print trap. I expressed this to their representatives, and the reply was shrugged shoulders and  "we can't do anything about it." They all seem in fear of losing their jobs, not a good sign for any employer - it means their personnel are barely qualified, have no other marketable job skills.
I didn't know what else to do other than re-establish my ATT internet and phone, because their equipment didn't work.  Despite all their concern about fraud, they seem blind to their own broken customer service promises and product misrepresentation. I can't yet decide whether to take my chances and return it via UPS, or just show up at a brick and mortar, drop it off, take a picture to document, just like Walmart, and walk away. Turnabout is fair play.T-Mobile needs stop the leveraging tactics against their customers. It's transparent to me they made little or no effort to serve this customer's needs, whatever the reason or excuse. I did as instructed and in good faith.

Regardless, one of two opposing scenarios exist: either they don't know what they're doing, or they do; i.e. all the obstacles and difficulties are intentional. I am not a stupid consumer.
I will send hard copy of this message via USPS registered mail along with the emails I received to corporate HQ and see what happens.