Straight Talk complaint: promised refund and now trying to refuse

Earlier in the year Straight Talk sent out a card saying the you will need to buy a new home phone modem or you would no longer have service. I did not purchase the new modem and was under the impression that the service ended. I called 8 times now, and 2 of those I was hung up on. The first person said I would get at least 3 months refund. The second person I got tranferred to said no. The third person said one month refund but then changed her mind. The fourth person I was transferred to said he would help me but I should call back tomorrow and he would help me contact the refund department giving me a number to call – He was MIA. I call today the person refuses. I call back 5 and get someone else who said they could cancel autorefill, but that only solves part of the problem. I get hung up on in transferring. I call 6 and get someone who again only talks about autorefill, and I get hung up on in transferring. Call 7 the same girl answers and tells me she is someone else. 8 I got automatically hung up on. How is this customer service????? This was unfair advertising. They have my number flagged in the system as told to me by the first representative. How can they be charging me when they tell me the service will not work without the new device. This is bad business period. They stole months of money from me, did not provide service, and with how big the company is there is no reason why I can’t obtain some sort of refund. This is an unacceptable dishonest business.