Greetings Newbie and welcome to Scuba Board!
Firstly I think that you are experiencing what many dive trainees have in the past.
Scuba is not a natural activity for most and takes some time to gain comfort and mastery of the 18 basic skills. This is very common to have issues in the pool and sometimes require extra time to gain comfort and skill mastery. This was the case for me and it was worth every extra effort and cost. When I hit OW I was able to pass with no problems. This was due to the efforts of DM Linda and MSDT Mark and a commitment by myself to conquer these issues. IT WILL GET BETTER!
Take your time and get some extra pool time so you all can have fun and enjoy diving!
After all it is supposed to be fun, the third rule of scuba HAVE FUN!
First rule; NEVER HOLD YOUR BREATH!
Second rule; NEVER PANIC!
5 hours is probably the average pool time but in many cases like mine it takes more to gain comfort and mastery of the skills.
Pool sessions are structured to allow you to gain comfort and practice the skills required to dive safely. It is the responsibility of the instructor to demonstrate and assist you in learning these skills. At some point you will have to demonstrate your skills to meet a satisfactory check off that means you are ready to perform them in OW. If you are not confident then ask for more pool time and be willing to compensate if it is required. I was more than happy to do so and it was worth it ten times over. The greatest thing I learned from the personal pool time was trust, confidence and determination. When I committed to conquering the issues it was over, that simple! Our brains can present us with individual specific challenges that take extra time to conquer, NO WORRIES! We can overcome, we will overcome!
Mask issues are a common problem to new divers! We all have purchased a ill fitting mask at one time or another. There are some awesome information here on mask issues and fit. Try the search here on Scuba Board to research them.
I will tray to be brief but fit is everything on a mask. Purchasing the perfect fit mask is a buddy required activity! Select a low volume, easy to clear mask and place it on your face in position. DO NOT SUCK IT DOWN YET!
Next have your buddy look for facial features that create opening or cracks in the seal. Try different sizes and styles till you find one that will seal without suction.
Then if possible try in the pool before you buy it. My motto is TRY BEFORE YOU BUY!
This is not always possible but many times is.
Are you being unreasonable? Returns are a part of business and a happy customer will always buy more than a unhappy one. My LDS would exchange it and move on no issues.
I would like to encourage you to stick with it, determine to conquer your issues and make the call once you have completed your training. I really decided after OW dive #1 that diving was for me. I immediately purchased all of my gear a week latter and that was just the beginning!
The adventure and journey has been one of the most rewarding experiences of my life. The places I have visited and friends i have met still blow my mind!
Hang in there and please PM me if I can be of assistance. I would love to help in any way I can. I am sure that many more will offer assistance as well but always that you are part of a community, the dive community and we have all came from where you are right now!
CamG Keep diving....keep training....keep learning!