Hi manazca,
OK … now I understand.
In the end you really only have two different options which would be either a local purchase or an online purchase (possibly from one of the suppliers in the online list for Canada I linked previously). When there are limited options available locally then an online purchase can make a lot of sense but only you can decide whether you are comfortable with an online purchase.
There is more about the different ways to choose a mattress and how to minimize the risks involved with each of them in post #2 here that may be helpful.
If you have neck pain then the pillow you sleep on may be very important as well. It’s quite common when you buy a new mattress where you sink into the mattress more or less deeply than the old mattress you are used to sleeping on that you may need a new pillow as well to keep your head and neck in good alignment. There is more about pillows in the pillow thread here.
Phoenix