Yoycol: Print on Demand

I really wanted to use Yoycol because I like their products. After weeks of back and fourth with their tech support via email, this app simply will not connect to my Shopify store. I get the same error message {"code":"100099","data":null,"msg":"Server is busy, please try again later."}
No one seems to know how to fix this. This is the only app on the Shopify platform that I have experienced this issue.

wir haben uns für Yoycol entschieden weil sie die Ioss Nummer zur Verfügung stellen. Und wir sind extrem happy. Die Produkte sind hochwertig verarbeitet, die Größen sind mit europäischen Größen zu vergleichen. Die Lieferung erfolgt relativ schnell ,obwohl aus China. Kundenservice ist Top und in den Facebook Gruppen findet man immer Hilfe und erfährt über neue Produkte sehr schnell. Wir bleiben gerne Kunden.

Updated 27JAN2023 - Still no product and no reply from customer support after three inquiries. Very unprofessional company - I suggest spending money elsewhere.
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Updated 24JAN2023 (Originally written 20JAN2023) - Downgraded from 2 stars to 1 star. Yoycal is not responding to any of my emails asking where my order is. It has passed their guarantee time by far and they are not responding to emails. I would strongly suggest staying away from this company - in my opinion, they appear to have some pretty major issues and they are all bad.
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Original Post - 21JAN2023
Second attempt at working with Yoycal so... shame on me.

First time - took 20+ days to receive half a dozen shirts. Took so long I almost forgot I placed the order. Products were good quality but what's the use if my customers have to wait three weeks or more for delivery? Had to drop them or loose my clientele.

Second time - had been watching the Yoycal site (because prices are good and product is as well) and checked web reviews found on other sites and saw comments that they were working on shipping times and customer service procedures (haven't used Yoycal customer service so can't comment on that). After a few months I decided to create a couple basic shirts (1 AOP tee and one simple front/back tee) with Yoycal as well as two other POD companies I haven't used before. One of them had me the entire order in six days, the other had one shirt to me in six days and the second shirt arrived the next day. Both companies have high quality tees but are also considerably higher in prices... BUT they both beat their expected delivery time by several days which is huge. We're now 11 days in to the order and status on the Yoycal order page shows the same status it has showed since day one - "Awaiting Shipment". Further research shows a label has been created (11 days ago) and the order has yet to be received for shipment. Once again, Yoycal has good prices and, as far as I still know, quality tees, but, if your competitors get orders out in a week, and my current provider gets them to me within that time frame as well... no matter how good your prices are Yoycal... I can't use you. I hope Yoycal can figure out their obvious major shipping issues - shipping times like this are a small business killer.