By default, unless you specify a tplPath property, getResources searches for @FILE tpl’s in the assets_path defined in your MODX config file + "elements/chunks/". If you changed the name of your "web_assets" folder to "elements", you could call the snippet like so:
[[!getResources?
&parents=`[[*id]]`
&tpl=`@FILE service_tpl.html`
&tplLast=`@FILE service_tpl_last.html`
&limit=`0`
]]
or you could specify the tplPath explicitly:
[[!getResources?
&parents=`[[*id]]`
&tplPath=`[[++assets_path]]web_assets/chunks/`
&tpl=`@FILE service_tpl.html`
&tplLast=`@FILE service_tpl_last.html`
&limit=`0`
]]