Contacting MWEB

I have been trying to contact technical telephonically to find out why some emails do not arrive in my in box. This is happening too often and mainly happens on a Thursday or randomly over a weekend. Incredibly one email arrived about two months after it was sent to me. These emails are all local, not international. MWEB technical *** gives you menu options which having submitted either my cell number or ID number then says they have no record of me. I'm like ***. Nothing connects to them at all. Where can I find a reliable ISP.