Thank God your Mom is asking and that too just for PER... My Wife directly asks me that when are we going to Canada... She does not want to listen anything about PER, AOR etc etc... :'( :'( So, you can say to your Mom if all goes well final decision will be made by Apr-May 2015 for you..
To explain further you can say that if "I would have sent my application on 1st May and also if my VO would have been CPC-O then I would have got the PR by now instead of PER"...
And simple explaination is that CIC is reviewing 5 to 10 applications per day but inflow of application is 30 to 40 per day
and therefore there is a backlog...
If nothing works then switch off your phone or add "Call Forwarding" to CIC customer center number and your Mom will directly talk to CIO and scold then what they are doing..