Terrible service and suspected theft

In December i got an Oppo A74, on the 3rd of May it stopped charging, when the battery died it never switched back on, i then got my sister to take it to Cell C Canal Walk for repairs, i never heard from the store until i contacted them 30 days later, i was advised that the phone had water damage and R6000 was needed for the repair as i do not have insurance, i advised them that i do not have R6000 so i would like the phone back so that i can make a plan, i was advised i would be contacted once the phone is ready for collection, i never heard again from the store and everytime i called either the phone would not be picked up or they would pick up and tell me that the manager would give me a call but she never did, i last month on the 24th i went to the store and spoke to the manager, she then advised that she had just requested that the phone be couriered back from repairs and that i would get the following week, the following week i never heard from the store and called several times 2 weeks later where i was told the phone had still not arrived from repairs, it is now 3 months since my phone was taken in by that store and i have been given a run around since yet i continue to pay for the phone.