Data credit taking months to get resolved.

Can I please have management give me call regarding my complaint as your ground staff clearly doesnt want to help me. I upgraded my contract on 15th May 2019 where I took a data contract for 24 months. This package included 20Gb day and 20GB night data for R200 per month the sim card only. Whenever MTN credits my account with data I only get 10GBs daily data for the month and 10GBs night Data per month. I've raised the query with MTN promenade where Mercia assisted with my upgrade and to date it has still not been fixed. She informed me that she needs to send document with a company letterhead to the head office explaining to them that the product code used from the booklet doesnt allow the account to be credited with the correct data on a monthly basis and I was very understanding as mistakes happen and I understood that it was not her fault but MTN head office or whoever sends the data to the clients on a monthly basis. I am however getting annoyed with her as she has now stopped responding to my WhatsApp msgs and she was the one who suggested that I add her on WhatsApp so that I can just msg her whenever I want to query how far they are with my credit of data. The centre agent are the worst as they everytime just tell me here is your reference number and we've escalated it. I'm always getting an SMS to say my query has been resolved but it has not. The only joy I've got from this is a credit of 5GB and the last time I spoke to the agent on the phone he couldn't even tell me how much was credited. So now I want to know... 1. When will I be credited with my 55GB day data as I've been paying the full amount every month and only been receiving half the service. On 12 Decemeber it will be the 7th month that I'm receiving half the service so I'll be in credit by 70GBs of data. If you people do not want to give my data then I'll be taking this to the ombudsman requesting that I get taken out of my contract by year 1 as I would have paid R2400 for half the data which means I'm only due to stay in the contract for half the term as im only getting half the service. Also if you people decide to credit me I would like to be ensured that this day data does not expire at a certain time as I'm entitled to use it till when its actually up. Please contact me ASAP as this issue is dragging out for too long and I'd like to get to a point of either being credited or moving my services to another provider who can actually manage something simple as assigning the correct amount of data to the correct client account.