As others say it may have been a request of creditors at your creditor meeting, or it could be that equity cannot be released from your property and therefore they have requested an extra 12 months of payments.
Your original proposal documents will give an indication of the length of IVA at the outset. If there was a change to this at your creditors meeting then your Chairmans report should state the change and may give an explanation as to why.
Either way....six years of paying a regular payment and then becoming debt free, is better than a continual cycle of only paying the minimum off the credit cards each month, living hand to mouth and worrying where the next weeks food money is coming from or where the petrol is coming from.....in 6 years time you will be debt free and able to start life all over again with your head held high !
Sharing from experiences of dealing with debt
There is a solution for everyone .... Just need to stay positive !