Hi, I have been an airgun enthusiast for 50 years and I received my first PCP rifle on Friday 15JAN2021. It is a Hatsan Blitz .22 cal. Yesterday, after reading the provided instructions I started to fill the gun's onboard tank with air from my hand pump. After pumping for about a half hour it became obvious that the gun leaks and would not hold air for more than a few seconds, preventing building any pressure at all. I followed the filling process exactly but the gun just will not hold air. Is there any easy fix for this, or should I just return it? I was really looking forward to testing the gun out, but for now it is a big disappointment. I would really appreciate any helpful knowledge.