Hello,
I'm a reseller and product uploader in shopify, I think I can help you Leena. When you list a product with variant in color or in size, you should change the SKU number and the UPC to make it work. E.g. If you have 040506WH sku for white and 040507BL sku for Black, you may notice that they have different SKU's and you should not list it in just with the first SKU you provided in adding products, that's why it won't subtract because it is just listed as one SKU. If you add variants is you must add also the 2nd or different SKU's.
I'm doing internet marketing on platforms like: Shopify, Ebay, Amazon and even Facebook developer and completed many uploading products with descriptions and pricing for 500 products daily. Before I upload my clients product images, I make sure that their images are captivating, clear and in high resolution to the audience.
Please view my profiles portfolio so you can see references with the feedback's I received. I have a PC here at home with fast internet connections and an 9-12 hours working availability.
I can even give you a free trial with uploading your 5 products for FREE WITHOUT PAYMENT to prove that I can do the task and further assure you that your money won't be wasted.
Hope to hear from you soon,
Ruel