Phone calls with child

So child is 7, in Court for 7 years, mom has tried to alienate son since birth. He is with me for 1/3 parenting time on way to 50/50.

I have two weekly calls in a window for 15 minutes each and it is suppose to be in a private room and mom continually breaches this Order in so many ways ie distracting and speaking with our child or telling him to get off the call, or simply not allowing call.

Next Court date, I am going to try to get video calls and ideally thrice weekly.

Any input or thoughts please on phone calls, video calls at all would be appreciated, ie what type of video call is best these days, and or the frequency of said calls.

When child is with me, I have always told mom that she can call him anytime or him call her, but she rarely does but when she calls or messages me I always facilitate the call immediately.

Thx