Dinner contract includes 22% gratuity

Just asked for a reservation at a restaurant for a group of 15 - they wanted a credit card form filled out in advance to hold the reservation- no problem with that - they asked for a $200 cancellation fee 24 hours in advance - ok with that - then in the small print it says a gratuity of 22% will be added to the bill - I have never seen that - I have seen 18% and normally up that to 20% but has anyone seen an establishment ask for a 22% service charge?

I am awaiting a response from the manager - I have requested a reduction to 18% on food and 10% on beverages - normally I would have paid 20% on everything but think they are being obnoxious asking for 22% - what do you think?