Microsoft Rewards Points problem : I can redeem points but I don't get any xbox card.

Keep in mind it can take uo to 24 hours to receive the funds. Before reaching out to their support, check your order history on the redemption site as it should give the option to either resend tbe funds or give a code to redeem for the funds.

There are,

You can go to https://account.microsoft.com/rewards/redeem/ and select any of the items there. There are entries in various sweepstakes, gift cards (I'm seeing Starbucks, Gamestop, Xbox Live, Xbox currency cards).

This page explains how to redeem the points: https://support.microsoft.com/help/20541/microsoft-account-redeeming-rewards-points

I think you are talking about adding goal in Microsoft Rewards. Once you have enough Rewards Points you can click on it and redeem. Once you redeem Microsoft Points, you will get an email with the code. You can then use that code to redeem on your Xbox,
or Xbox app on your phone or PC to get the gift card balance.

If you redeemed your rewards points for a Microsoft gift card or Xbox gift card, the balance should automatically be added to the account balance for the account that redeemed the points. They don't send you a code typically.

Can I use Microsoft Rewards to buy rubies or tools from the Microsoft Store for Hidden City, Hidden Object?

I don't think there are any offers to use MS Reward Points to purchase ingame items in the way you mention.

but you might be able to redeem the points for Xbox/Microsoft Gift Cards then use your Microsoft Account Balance to make the ingame purchases