Tmobile problems on my return of phone

wow this is unbelievable, we too started with nextel who sold out to sprint who sold to t-mobile, to which customer service has declined since nextel,  we were going to try t-mobile business internet however after receiving the router we realized in my business shop it is a metal building with a metal roof and their phone service (signal) is awful out there so a wireless router was not going to work, I reached out to them immediately because I have a 15 day free trial if you don’t like you can return, I keep getting suggestions as to a different method of service to try, wireless will not work Period! and have been told I should get a RMA label within 2 days it’s now 7 days,  I think they are  stalling to go beyond the 15 days then try to charge me for the router, I also haven’t been able to access my online account for 3 months, I have to call to make a payment  but was finally told I have a fraud alert flag on my account preventing me to have access, Now why wasn’t I informed of this, we did uncover a incorrect e-mail and an address that never existed, that was suppose to be corrected but I still can’t access my account online, I currently have a cable hardwire internet service that I’m glad I didn’t cancel first so I can continue working, I do have the return address that I received router from  at 13704 Independence Parkway Fort Worth Texas, that I’ll pay to return myself, reading these reviews and comments it sounds like they are disputing/denying receiving any returns, maybe time to get a lawyer involved