Request to change repayment period

On the 7th May 2015 I called standard bank and requested that they calculate for me what the instalment would be if i were to change my repayment period from 30 to 20 years. The lady that i spoke to said it would be R3768.03 and then i made the request that the period be changed. To my dismay i got an sms from standard Bank confirming the change and indicating that my new instalment would be R4832.72 which i cannot afford. I immediately (on the 11th May) called them and faxed another request that they change the period back to 30 years as i wont be able to afford it.<br> <br> I didn't get any response from them and called again on the 27th May and was advised that my query is still in progress. I then called again on the 1st of June and was referred to another department which is not really assisting me.<br> <br> My request is that my home loan be changed back to 30 years as i cannot afford to pay the new instalment.