Snap,
Your problem is most likely due to a Telkom transmission link failure on the Shelly Beach 3G site resulting in the site being down - thus no 3G coverage. I presume you are using a 3G only profile - try a GPRS profile. The fault should hopefully be resolved shortly.
15h35. Telkom still busy on fault.
16h15. Link repaired - site back on air. Snap, please confirm all OK now.