LOYALTY POINTS

I bought 500mb with 6600 loyalty points @10:06 am - by 10:37 it was gone. I was in a 30minute meeting, my phone was next to me. All i got out of the 500mb was 2 Whatsapp messages shortly after I loaded the bundle. Call MTN and they tell me i used the data? WHEN AND HOW? I never even went on the things the said used it. I AM FURIOUS! Like 500mb lasts me usually like a week but now suddenly it lasts me 30 minutes and i did not even use my phone? my data as a whole is restricted to certain apps while i am not on my mobile data. No help from MTN and I have been a loyal Customer for as long as i can remember.. This is so annoying. I am always championing MTN and telling everyone how perfect the service is.. Customer service just blames. Annoyed and thoroughly disappointed.