No responses to e-mails/enquiries makes an unhappy wiki

Last week due to writers files and images becoming too mixed up with administrator files and images in the edit pages I was forced to make the decision to upgrade my wiki to the classroom level.
However my credit card was not accepted with no reason given.
I wrote an enquiry to the billing section (Case #00067555) ref:00D78eKn.50078TuWw:ref and did not hear anything for several days.
I again tried to upgrade, my card was again rejected, again I wrote to the billing department (Case #00067647) ref:00D78eKn.50078U2RB:ref, and yet again I have not heard anything after several days.

This is not the first time that enquiries have not been answered. Last year I applied for the presenters pack as I was giving a presentation on my wiki at a conference and also I did not hear anything from you. Does the presenters' pack even exist?

I have put a lot of time into building and putting together my wiki and this lack of response is not building my confidence in the service

I have been forced to make the upgrade and need to make this separation between writers files and administrators files in edit pages.

I would appreciate a prompt reply and some immediate help.