Dont care attitude to retain customers

i am due for an upgrade and was offered a good deal from vodacom as i was a client for 10 years with them and then moved over to cell c. Time to upgrade i was convinced by the rententions dept at Cell C that they can match the deal,well they came close which i then told the agent o give me a day to consider and i will get back to him,told vodacom sorry i am staying with cell C.Called back the following day to give the go ahead to upgrade my 1 of 2 contracts with cell c.I left several messages to be called back and to date and 3 days later cell c doesn't bother returning calls or even acting upon the complaint logged on via their app.Guess what Vodacom has bettered the deal as well by throwing in an additional pay as you go deal with a samsung handset together with my iphone X.Cell C should learn about customer retention especially when a customers account is maintained so well. Vodacom is willing to pay up my early cancellation fees for my 2 cell c contracts as well,thats what I call service. CELL C wake up if you are trying to compete with the big dogs inn the market.You will loose customers just as quick as you gain them.....