Bad service

Good day

My name is Nokuthula Nkosi I had a contract cell phone with Blue lable in 2021within a month the phone hade a problem and I reported it thy come to collect a the phone and give a new 1 but still the phone the same problem and they wanted to give a 3rd phone of which it was the same thing so I asked If thy can give me different brand phone thy said no. I Spoke a lady by the name Refiloe and she promised to call me back once she get some answers regarding the fone but she didn't call back. I called thy offices and spoke to a Guy by Thabang and I explained the problem he said he will speak to his Manger he cam back at old me that his manager/supervisor said thy gave a an exceptional cancelation and that I have to bring back the phone with all it accaseries and I did he also told me that I won't pay any fees. The courier service come and pick up the phone in January 2022 now I keep on getting calls and sms saying am owing them whn ever I tell thm thy said thy will look into the matter till now no feed back from them I real don't know wht to do. Pls help