I am talking about the clip/charging clip etc and this as an accessory as I already have the headphones and don't want to buy another one just because I am missing the clip....

If you mean the charging cable or the charging clip, that is included in the delivery. Only the USB charger itself is not included, but by now everyone has several of these.
Here is the list of contents according to the technical description:
CONTENTS
- Wireless in-ear headphones X3
- Silicone earpieces in 3 sizes
- Secure-Fit ear inserts in 3 sizes
- Cable management clips
- Clothing clip
- Charging clip
- USB 2.0 charging cable
- Sports carrying pouch
- Earpieces from Comply in
3 sizes (sport)
- hope this helps