Email delays causing major problem

Since around 8 November, my emails are only getting through to me many hours after being send (including 'test' emails to myself from Vodamail as well as Gmail. I reported this on Sunday 19 November and was given the following reference : *** and was told to expect resolution within 24-48 hours. Having heard nothing from Vodacom, I telephoned the help line again at about 0940 today (15 November) and was told the matter was still under investigation. I asked to speak to the supervisor bur was told she was in a meeting and would call me back. I wonder if this will happen !! This problem is having a major impact on my small business as for a number of applications I use a verification code is sent to my email address as part of my login. As I am only getting emails sporadically (sometimes many hours after they're sent) I cannot login to these.