Customer Service without the Service

I have had my contract with Cell C for 2.5 years and at its inception I asked them to set a limit on my usage so I did not get any surprises and up until last month they have comp**** but for November and December they decided it was not necessary to comply. I have complained constantly about them sending my statement in infoslips format as I struggle to open it and have requested on 5 previous occasions to send it as a pdf document which never happens. On 31 December I sent an email requesting some feedback as to why my account had gone over the set limit and 7 days later I await a written response. Service what service they are a joke