I agree with previous responses, Iran is really strict about using VPN, it's like China where many of such services don't work too or work but very slow. Anyway they can't block
everything and there are VPN services which can be used effectively even in such countries. But yeah, be careful with using them!
I really recommend you to pay attention on such tips while choosing the one:
- your VPN should keep you safe and overcome these blocks for net so your the most important things will be anonymity, privacy and security
- it should have a really high level of safety so check firstly your VPN service geographical location and its privcay policy (reviews from other users are really helpful in this case too!)
- it should provide a good speed (in your case it's possible only for paid ones, not free services)
- it should cover many locations which will make your general choice better and safer
- your VPN service should be synchronized with your platform (not all of then can work on all platforms so don't be lazy for checking this)
I think that your best in case of services will be something from the ones which are used effectively in China too (because as I mentioned this country is very similiar to Iran with their restrictions for VPN) like for example ExpressVPN, KeepSolid VPN Unlimited
https://www.vpnunlimitedapp.com/en, VyprVPN, Astrill
https://www.astrill.com/pricing, Buffered VPN, AirVPN and StrongVPN.