Poor Service unable to solve a simple data query

I upgraded effective 1August 2017. The contact involved 3 months of 10GB a month. On 31 August 2017 I received the following SMS from MTN: MTN apologizes for not giving time to enjoy the 1st of your LTE FREE 10GB X 3 months, so we have added a complementary month. Enjoy. Ts&Cs. I received for Aug, Sept and Oct. The promised complimentary month did not happen. On 15 November 2017 I contacted the call center via 808, and logged the following ref: 1- ********** 2854. I contacted them again on 17 November to follow up in which they said the query had been escalated. Today, 7 days later, I followed up and spoke to a team leader. He advised that my query had not been seen to after I was promised that it would of been sorted 72 hrs when I first called in. What made me angry was the lack of concern or deadline to a query. I get the feeling that my query will never be attended to. I am not happy with the level of service received seeing that I have been an up to date customer for many years. I would like my query to get attention.