As per TRAI rules, a user subscriber is entitled for call data as a matter of right and he has the right to be informed by service provider.
There is no part of Police in obtaining individual data of one's own phone call details.
Issue a regd., local notice to service provider, wait for one month after receipt, then file complaint in District COnsumer Forum for service deficiency, explain the urgency to President and pray for interim order, seeking compensation for deficiency of service and harassment..
If it is a Govt., company, seek information under life and liberty clause and you can get the same within 48 hours from them under RTI.
But remember, that the call details are made available only for three months and periodically deleted.
Though it is proper that burden of proof is on the other party, it is always better to equip ourself with all possible deenses to counter them.
I am afraid that retrieving one year old data may not be possible as per my knowledge.
You can only get court directions if the data is available and Court will give such directions immediately.