Phnom Penh Thai Embassy: Hard to get VISA now

Hi everyone.
I’m Italian and I have been in Thailand for the first time with a SETV60 days + 30 days. After that I extended for another 7 days to match my flight date and avoid any overstay on my passport.
However now I flewout from Thailand to Phnom Penh with the idea to visit the city and eventually get a new visa before going back. So I went to the well reviewed Lucky Lucky visa agency in PP and I got really surprised when they told me that nowadays almost 50% of visas get voided.
They also told me from their experience thatif you previously extended your SETV atThailand Immigration Office , 90%of the times your Visa will get voided if you apply. And that makes things even harder for people to get a new VISA in cambodia.
So I started thinking about applying for a new one.
On Friday 22th feubrary 2019 I’m trying to go back to Bangkok and try to get a Visa exemption ( it will be my first one ) .
So, instead of trying the luck with a new SETVand eventually get a voided oneon my passport,I decided to save the 50$ and spend them on a newflight out from Thai ( for Vietnam On the 24th march, after exactly 30 days , just in case I need toshow as a proof of onward ticket to airport custom).
My question is: does anybody know if there is any chance they’ll refuse to give mea VEflying back to Thailand from Cambodia?
Considering thatI never attempt to get a VE before,I will have20000 baht cash in my pockets,Proof of onward ticket out of the country after 30 days and rent contract of my condo.
Do you guys think they will say like “you cannot get in another time” ?
I really need to get back because I still have all my things in the condo.
Can anybody tell me his/her opinion?
Thank you so much guys I appreciate any answer.