Hi @Bv420 thanks for your post here in the Community, welcome!
It's unclear exactly what you mean here so I do apologise, but if you have a Volt package, then your M350 speed may be boosted to M500.
However, you would always receive what is stated on your contract - if you are unsure or haven't seen your contract, please don't hesitate to let us know!
Many thanks
Tom_W