Payment buttons is not click-able, Please check http://pahasu.lk/cars-vehicles/three-wheelers/2-stroke-threeweel_i20945

@emmazz
You have javascript error on that site, some scripts in your installation were not included by osclass rules.
I gues this one is problematic:
Uncaught ReferenceError: LazyLoad is not defined

this theme is your's and it's customize by You ( as hosting issue )

how to fix that ?

@emmazz
PM me login to your FTP and oc-admin so I can investigate what cause it.

check inbox

@emmazz
You are using some module or script, that change for every javascript from:
<script type="text/javascript">
to:
<script type="text/rocketscript">
Can you please disable it?

@emmazz
Got it by myself adding this tag to script:
data-cfasync="false"
Everything should be ok now.

it's loading well on Lumia 925 mobile device.

Ok, Thanks

<script type="text/rocketscript">  how did u found that ?

@emmazz
Found in source code, googled how to avoid it.