did he give you a time for completion.the only time he can charge storage is when the job has been completed as agreed and if u don't pick it up the day its ready. he has to let u know that storage fee now applies in writing once the job is finished,if u pick up job 1 week after completion and u where notified of storage fee then u have to pay, eg about $25 per day if under cover,about $15 a day not under cover. if job not completed and u chose to remove car, he can only charge for what his done, it not your fault he didn't complete the job in the agreed time. , i don't think he has a leg to stand on legally. cheers