AT&T BURLINGTON MALL, MA bought LG mini pad for $1, not told of 40 activation charge, monthly billing, insurance and 2 year contract plan burlington Massachusetts

I went into the AT&T store at the burlington mall in June 2015.  I purchased a contract to buy a cell phone.  they had a special to get an LG mini pad for just $1.  i was not told of a $40 activation fee, 2 year contract, $40 a month minutes,data and $6.99 for insurance and $10 a month installment plan.  I thought it was just a $1.  I received an outrageous bill.  called AT&T on July 19th.  they apologized, said this happens all the time.  that the salesman didn't explain the terms.  They said they would waive all charges and activation fees; and i could keep the LG pad for just $1.  I paid the bill due in Full for $53.88.  then last week i received a text from At&T that I owe $170 in back charges on my cell plan and they will cut my phone.  I call At&T and they cannot return my money until I go into the AT&T store and return the LG mini pad.  I go into the store to return it and I am not allowed to.  It would cost $175 in cancel charges.  I was extremely upset.  I spoke up to 5 people waiting in line that At&T is ripping off their customers.  I told everyone in line to check their bill; that if they bought a mini pad for $1, that they are paying charges not disclosed.  2 people in line had the same problem.  they had been told only $1 charge and had the same insurance, data, minute charges on their mini pads also.  They were also told there was nothing they could do.  that the person who sold the products was fired.