Odsp orthotics question?

So I have a appointment with the chiropodist this Saturday to get fitted for orthotics. How easy is it to get approved from what it sounded like when I was at the ODSP office this past Friday all I had to do was get the owner of the orthotic place to send an email with the prescription but how long does it typically take? I would rather get them sooner than later and I also would rather not have to pay out of pocket for them as if I did pay I could have them the same day within a few hours I gave up trying to contact my caseworker as every time I left a message in the past they never respond so the only way I could see about getting a response would be going to the ODSP office which is annoying every time. I'd have a simple question

Any help would be greatly appreciated