Data query

Hi there I'm frustrated with the service at MTN,I've got a data contract with them and I receive my data on the 2nd of each month. I was working nite shift and all my all time data was being use instead of my night owl data and had to make six phn calls before I made contact with the manager who informed me that it was only 800 MB and nothing more,which he said he will make contact with me and I even gave him my email address and I'm still waiting