Missing reward for a quest

I guesss nothing yet still missing jan and feb quests rewards

if you do the quests but don't receive the reward points go to https://account.microsoft.com/rewards/ scroll to the bottom of the page and click the link to Contact Microsoft
Rewards Support.

that will open a support ticket where you can give details of the quests you have completed and the amount of points missing

Phone support suggest to direct message a member of the forum and give him a "reference" number to check it out. So far, no response.

No one in the forums will have that information. You should contact support again to try to get your issue resolved. https://support.xbox.com/en-US/contact-us

The problem is, phone/chat support do not handle promotions. Only support in this forum handles them but they have not been posting.

Since quests are not part of the Rewards program (Xbox or Microsoft), Rewards support will not be able to assist. The correct forum would be the Sales and Promotions forum, but support in that forum has been MIA. The only other advise I can give is to try
tweeting @XboxSupport to see if they can assist (if you have Twitter).