Troubled customer

Good day, as a valued customer for quite a number of years. I am terribly disappointed in your service delivery. Last year I took out a new contract with cellc for a new samsung device. This year it started giving problem and on 12 August 2018 it was received by cellc to fix. I got it back and worked perfect , but only for about 2 months. Last week I sent the phone back for repairs, just to be informed by cellc that the only way they can fix the device; would be for me to pay almost R1000 for a new battery, as the warranty on the battery as expired. I'm all for rules and regulations, but please explain to me why after 2 months the device gave the exact same problems, after coming back from repairs. Then I'm expected to pay a large amount of money for a device that clearly doesn't live up to its standards. Then when I go on the samsung site, they request for me to pay R490 to speak to a technician... how can customers trust your products to work if the products do not even last a full 2 years and then customers are expected to pay your company loads of money, just to fix an inferior product that might not even work.