Some customers who recently ordered speakers from Sonos’ website received more than what they ordered, which normally wouldn’t be something to complain about — but Sonos charged extra for the devices sent in error and wants them back. While Sonos is providing users with a refund for the additional charges, some are still disappointed they weren’t offered a discount for the inconvenience of dealing with a problem they didn’t cause.

Two separate users told The Verge they placed an order for a single Sonos Move and received three. Another user said they’ve been charged over $2,000 after ordering one Move speaker and receiving a total of seven. They say Sonos has given them a timeframe of up to 10 business days until they get their refund.

There are also plenty of other reports in a thread on Reddit that indicate the issue affects more than just the Move — other users ordered the Roam and Ray, with some saying they received (and were charged for) anywhere from two to five extra speakers.

In an emailed notice to users, Sonos informs affected customers they “have been overcharged” and “will also receive multiple shipments” of their order. Sonos blames the problem on a system update that resulted in “some orders being processed multiple times.” The company asks that affected customers ship the extra speakers back with a provided prepaid label and says they can use Sonos’ carrier for pickup.

You can read the full message below, which is signed off on by Ruth Sleeter, Sonos’ chief information officer:

A recent update to our systems resulted in some orders being processed multiple times. Unfortunately, you were affected by this error and have been overcharged. You will also receive multiple shipments of your order.

I want to personally apologize for the inconvenience this has caused. You will receive a full refund for any excess orders and should see the credit issued to your account within 10 business days.

You will also receive prepaid return labels for any excess orders to this email address within 2-3 business days. To make this as easy as possible for you, we are happy to schedule pick-up with our carrier. Please reply to this email or call our priority support line at 1 800-680-3527 between 7 AM and 4 PM PT, Monday through Friday.

Again, we are truly sorry. Thank you for being a valued customer and supporting Sonos. Issues like this are rare, and we will do everything we can to make it right.

Please don’t hesitate to reach out with any additional questions or concerns.

We don’t know how many customers were affected by the issue or when the problem first started. It definitely isn’t good for Sonos, though, and it’s unclear if there are any consequences for those who don’t return them.

Sonos may not be able to legally charge customers who don’t send them back. A post on the Federal Trade Commission’s (FTC) website says “you never have to pay for things you get but didn’t order” and that “you also don’t have to return unordered merchandise.” website. The Verge reached out to Sonos with a request for comment but didn’t immediately hear back.

Update June 13th, 6:49PM ET: Updated to add more detailed information from an affected customer.