R750 Promotion not honoured

Hello Peter<br> <br> Please help. In April I joined Discovery as they had a promotion of getting R750 back paid over 5 months as cash back. I joined in and they told me I have to activate my healthy food benefits. Due to internet access and my phone issues I called them and they ended up activating my healthy food. The agent I spoke to confirmed that it will be paid over 5 months. I was ok with that and had no urgency of the money. I called a few days back to enquire why am I not receiving my cash backs? They told me I activated my healthy food benefit 5 days after the deadline. I told the agent that no one told of the deadline. they insist they told me to activate healthy foods. Yes I know that but there was no deadline to do this and getting a cash back. I need my vouchers as this is the reason and incentive i joined vitality.