Desktop players converting over to the PC EA should still see a coin balance of the seemingly worthless silver coins due to their progress up the levels.
WGT consistently (well usually consistently) issues 100 coins per level achieved on the mobile platform. When a long standing member tends to jump onto mobile whether it be to keep a CDP going or something else, they will often see a sudden influx of silver coins they had not previously earned. They are sometimes baffled where these came from, since they never played coin games.
The issue or concern is whether WGT is issuing these correctly for longstanding members who have earned their silver coin level bonuses from playing WGT primarily on the desktop platform but simply may not have been a regular mobile player.
I found a way to easily calculate how many coins you SHOULD have. If it deviates significantly from what you have been given and have not been playing or spending coins then the numbers should match up pretty close if not exactly, unless you were playing the daily slot, random scratchers, etc.
Obviously, once you start spending and using coins, your balance can fluctuate quickly.
But a quick estimate is the following -- (level (level+1) / 2) * 100 = projected coins
EX - for level 100 --- (100 (101) / 2) * 100 = 505,000 silver coins from level up bonuses.
You have earned these imho, progressing up the levels in a similar fashion to mobile players, so you too are entitled to your full silver coin level bonus. If you didn't get the full allotment, I would suggest contacting Customer Support. *
-- just a suggestion... play responsibly... while you may have received a lump sum of coins seemingly without effort... you can lose them rather quickly in the larger stakes coin rooms. Even experienced mobile players go on losing streaks that can wipe them out if they don't manage their silver coin bankroll properly... and unless you buy them, it takes a lot longer to build up coins in the very low stakes coin rooms compared to the mid to upper stakes coin rooms.
update
* - keep in mind coins were released approx. Dec 2015. WGT levels achieved prior to that time were handled differently. I can't confirm exactly how many or what they did. So, if long standing members have any remote idea what level they were at then, you would use the formula for that level and subtract those coin level bonuses from your current Level after applying the formula to have a more accurate estimate, given you have been around so long.
Ex: A long term WGT user who is currently L146, but was likely L98 in Dec of 2015 --
Current level Progress - Levels when coins didn't exist = projected coins
((146 *147) / 2) * 100 - ((98 * 99) / 2) * 100 = 1,073,100 - 485,100 = 588,000
this would not include scratchers, 1 arm bandit, or other bonuses like the possible 5000 or 30,000 bonus that may have been given out upon initial release of the silver coins.
We don't know what WGT is doing, just yet, with the real long term and level chasers beyond L200 which appears to be the highest level you can reach right now or whether any level bonuses are being given at any type of increment.