I recently uprgraded to 50/50 with a new router and all that jazz. I had25/15 (I think). I have been having such connectivity problems recently that I even called and had them send me a new router. With the new router, same issues. I call into a technician and we test my speed. 17/17. I then asked why I am paying for 50/50 and getting 17/17. He went on to list excuses of wireless vs wired. I am 10 feet from my wireless router (in the same room). The technician then told me that "17/17 is good" after we tried a channel switch. I understand 17/17 is good, but 50/50 is what I am paying for. I understand there is loss in signal, but to lose 66% of my download speed (yes I calculated it) is redicilous. I have had fios for 4 years and with my recent upgrade they havent changed any of the hardware outside my house or in my garage. When asked about this the technician told me I didnt have a claim unless I hardwired my pc, checked the connectivity, then I could complain. So in a world of smart devices, tablets, and the such I'm not allowed to officially complain to verizon unless I can hard wire a device and prove that I am recieving 66% signal loss in 10 feet with "no detected signal intereference" from their testing site. It's terrible. I am actually tempted to go buy something I can plug in to prove that I am not recieving the product I am paying for.
WiFi is subject to all sorts of issues that can impact speed. No ISP guarantees WiFi speed.
You absolutely should test with a wired connection. If you can't get 50/50 from the Verizon speed test page, they should look into it for you. But only if you test with Ethernet.
If you find it works properly with Ethernet, there are several things that can be done to improve WiFi performance. Post back with the specific router model you have and some of us users can give you suggestions on how to get the most performance from it.