Why are customers being charged extra for shipping?

[JTH]

Hi,

My shipping are set up with free shipping within Canada over $99 and $15 flat rate under.

Since today, customer are being charged $15 when the free shipping should apply and $30 when the flat rate should apply.

[Richie_Ramone]

Same here.

A customer called me Wednesday, saying although the order he was placing reached the $160 free shipping threshold, the system was charging him. He went ahead and placed the order, using his VISA, and yes it has charged him shipping, which I now need to refund.
Today, another regular has placed an order (totally different products) and now emailed me to say he too could not get the system to provide free shipping. He used M/Card.
I checked all FREE SHIPPING orders received since Thursday and most have used PayPal but I see one each for VISA and M/Card that successfully had free shipping applied.

So there is no clear and obvious pattern to when the free shipping is not working but what is apparent is @Shopify  needs to fix this URGENTLY.

[sniper2804]

Hi, 
This seems to be like a case of products present in cart from two different shipping profiles or two different locations. Is that the case in the affected order? 

[Richie_Ramone]

Not sure whether you're you're replying to me or the OP, but my items are only stored at one location. Yes, there are multiple shipping options (not sure if that's the same thing as the "profiles" you are referring to...)

[MiraPatil]

Hello @JTH 

i think this must because of multiple locations on your store. 

i have a solution using app: Shipoff: Shipping Offer.

in this app, you can set max shipping price like below screenshot:

i hope this works for you, let me know.

[DavidNZSSI]

Hey JTH, I would take a look at this guide: Shopify Help Center