Update membership price issue in Membership 2 plugin

Dear Team,
I've created four memberships using Membership 2 PRO plugin.
I met 2 issues: first is the caching: I change the price for membership but once i go to signin page, i still see the old one and the old one is sent via payment gateway for purchase.
Please, help me to fix the issue ASAP.
I would have to create another packages with the new prices right now as the site is live and i cannot effort having issues like that.