Do I seriously have to pay for service I have never used?

I do not understand how they are calculating an amount of $60+tax at first.

With T-Mobile, you mostly prepay your monthly plan. What is truly a postpaid is the additional charges.

Technically, you should not be charged before activation of your SIM card. If the SIM card were activated even before you receive them, then it's not correct.

But returning the package, without a phone call, normal that you are receiving a new bill.

Normally, you should have been aware of how much you were going to be billed upfront.

Regarding your experience, this is why I am always going to the store (speaking with their incompetent reps, but at elast they can tell you upfront what you are going to pay).

Have you been calling T-Mobile after refusing the package from UPS ?

If no, the time it's getting back, it can take time to process, and this is why you get billed again, for the following month. But $66.87 makes no sense.

So, technically, you have been subscribing to a service. If you did not cancel it, then, again, technically, you should pay for that service.

So, I would with no time try to enter in contact with them through their T-Force, using Facebook Messenger (open the facebook page of T-Mobile, and click to send a message through Messenger), and explain the situation. They may be able to work something for you. FInger crossed.

If you are calling their team of expert, at first, they are far to be expert of anything, they may be rude, and of course, nobody is going to solve your issue.

Good luck.