Telkom ripoff

bought a cellphone on contract from one of Telkoms tores, had to take the device back to the store because of some factory faults, the cost of the phone was about R30K, received a call from them telling me i had to pay over 40k (an amount far more than the device) to have the phone fixed, even though i had the phone for a couple of days, i was not willing to pay that amount, never got the device back and they claimed they will cancel the contract i had with them. recently received news that i owe telkom 38k for a phone they took back and never used.... went to querry with the store, they cant locate the device and have no idea what is happening