MrDelivery customer service needs to be updated

Horrible service!, I tried charging my email address on the app by their system does NOT allow you to do that. Ended up calling them in order to do this and spent a long time on the call. I insisted on keeping the advisor on the line this time as this was the 2nd time doing this without my email being updated. After logging off and back on I try using my credit waller +-R145 their system says I have zero credit wallet. Called them 4 times and they're not answering calls they all just drop. This was the grocery piick n Pay section.